Add TLS fragment support

common/tlsfragment/public_suffix.go

@@ -0,0 +1,55 @@
+package tf
+
+import (
+	"bufio"
+	"bytes"
+	_ "embed"
+	"io"
+	"strings"
+
+	"github.com/sagernet/sing/common"
+	"github.com/sagernet/sing/common/domain"
+	E "github.com/sagernet/sing/common/exceptions"
+	F "github.com/sagernet/sing/common/format"
+)
+
+var publicPrefix = []string{
+	"www",
+}
+
+//go:generate wget -O public_suffix_list.dat https://publicsuffix.org/list/public_suffix_list.dat
+
+//go:embed public_suffix_list.dat
+var publicSuffix []byte
+
+var publicSuffixMatcher = common.OnceValue(func() *domain.Matcher {
+	matcher, err := initPublicSuffixMatcher()
+	if err != nil {
+		panic(F.ToString("error in initialize public suffix matcher"))
+	}
+	return matcher
+})
+
+func initPublicSuffixMatcher() (*domain.Matcher, error) {
+	reader := bufio.NewReader(bytes.NewReader(publicSuffix))
+	var domainList []string
+	for {
+		line, isPrefix, err := reader.ReadLine()
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return nil, err
+		}
+		if isPrefix {
+			return nil, E.New("unexpected prefix line")
+		}
+		lineStr := string(line)
+		lineStr = strings.TrimSpace(lineStr)
+		if lineStr == "" || strings.HasPrefix(lineStr, "//") {
+			continue
+		}
+		domainList = append(domainList, lineStr)
+	}
+	return domain.NewMatcher(domainList, nil, false), nil
+}